This invention relates to the control of a heat pump system having one or more zones that may be requiring different amounts of conditioned air at any point in time. In particular this invention relates to the control of the heat pump system when at least one zone is to respond to a significant change in the temperature set point for that zone.
Multiple zoned heating systems will typically have individually programmed set point temperatures covering a day or a week at a time. These zoned heating systems will often undergo a significant change in set point temperature when for instance one or more zones switch from a night time setback temperature to a day time temperature. In such situations, a tremendous demand is sometimes placed on the heating system to provide the heated air to these zones.
The ability of a heat pump system to quickly respond to such a heat demand may be less than adequate. In this regard the one or more zones may each be requiring a significant change in temperature that cannot be achieved quickly by the heat pump itself. Heat pump systems often have an auxiliary stage of heating to supplement the heat being provided by the heat pump in such circumstances. These auxiliary stages are typically electrical resistance heating devices that consume considerable power when in use. This electrical power consumption tends to offset the economical savings of the heat pump itself.